In this lesson, we'll take a look at an inhabitant of the world's oldest lake: the Baikal seal. You'll learn about its habitat and predators, as well as some adaptations and interesting facts.

Pusa Sibirica

Can you imagine if you lived in a place where you were trapped by three feet of ice every winter? This is normal life for the Baikal seal (Pusa sibirica). It is not unusual for the ice on their lake to be up to three feet thick in the winter. They deal with it by spending the winter keeping their breathing holes open in the ice, so the holes don't seal up. Males often spend the winter underwater, keeping their holes open from below. Pregnant females, on the other hand, are more likely to be up on the ice. Either way, maintaining a breathing hole in three-foot ice is no small task.

Male Baikal seals often spend the winter underwater

Habitat

Baikal seals, as indicated by their name, are endemic to Lake Baikal in Siberia, which means they are found nowhere else in the world. Admittedly, the lake is enormous. At 12,248 square miles, it is one of the largest lakes in the world. It is also the oldest lake in the world, dating back at least 25 million years. The size of the lake allows for a fairly large seal population (more than 80,000), even though this is the only place they are found.

Baikal seals are the only completely freshwater seal species. Lake Baikal is a freshwater lake, and the seals almost never leave the lake. They do occasionally swim up the connecting river, but even then they later return to the lake.

Adaptations

Baikal seals have a number of behavioral adaptations that help them survive in their environment. One is that they move around the lake depending on where food is located and what the ice is doing. In the winter, the seals are widely spread throughout the lake and mostly live alone. In spring and summer, they come together where there is more food. In fact, in summer the majority of the seals gather in one section of the lake, where there are rocks and beaches so the seals can come out of the water.

Additionally, they have a seasonal birth cycle. Pups are born in February and March, which means they are weaned (they move from milk to solid food) about the time the ice is melting, and food is more abundant. In fact, weaning appears to be directly connected to melting ice. In areas of the lake where ice melts sooner, the pups are weaned sooner.

Baikal seals gather in groups during spring and summer

Predators

You may have noticed that none of the seal's adaptations are related to predators. This is because Baikal seals have very few natural predators. The brown bear is the only known animal in the area that hunts these seals. However, Baikal seals do face hunting threats from humans. When they are threatened, Baikal seals will dive. They actually have more blood than other seals of their size, which means they can hold their breath for longer; up to 70 minutes!

Interesting Facts

The Baikal seal is quite an interesting animal. For one thing, scientists actually have no idea how these seals came to live in this lake, or how exactly they are related to other seals! Another interesting fact is that they have a gestation period (the length of time the mother carries the babies before giving birth) of nine months, just like people. Finally, it is not uncommon for Baikal seals to have twins, even though twins are rare or nonexistent among most seal species.

Lesson Summary

Baikal seals (Pusa sibirica) are endemic to Lake Baikal in Siberia. They have many adaptations to help them live in this harsh environment. In winter they spend most of their time keeping breathing holes open in the three-foot ice. They also scatter across the lake in winter and gather together again in spring and summer. Baikal seals have a seasonal birth cycle so that the pups are weaned just as food becomes more available. In areas where the ice melts earlier, pups are weaned earlier. Their only natural predator is the brown bear, though they are hunted by humans as well. Baikal seals will dive when threatened. They have two liters more blood than most seals of their size, so they can hold their breath much longer. Baikal seals have a gestation period of nine months, and they are one of few seal species to have twins. Interestingly, scientists have no idea how they came to be in the lake, or how they are related to other seal species.

Summary:

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